Semiconductor memory device

ABSTRACT

According to one embodiment, a semiconductor memory device includes a casing, a substrate, a second connector, and an interposition member. The casing is provided with a first opening and includes a first edge forming the first opening. A first connector conforms to USB Type-A standard and can pass through the first opening. The interposition member is interposed between an inner surface of the casing and the second connector, is held by the inner surface, and holds the second connector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2018-048146, filed on Mar. 15, 2018 theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a semiconductor memorydevice.

BACKGROUND

Semiconductor memory devices include a connector for providing aconnection to a host device, for example. The sizes and shapes ofconnectors variously differ in conformity with standards such as USBType-A, USB Mini-A, USB Mini-B, USB Micro-A, USB Micro-B, USB Type-C,and Lightning®.

The connector projects to outside of a casing through an opening of thecasing. The openings of casings are variously designed in size and shapeaccording to the different connector standards. Because of this, eventhe casings having substantially the same design need to be individuallydesigned and manufactured according to the connector standards.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exemplary perspective view illustrating a flash driveaccording to an embodiment;

FIG. 2 is an exemplary exploded perspective view illustrating the flashdrive according to the embodiment;

FIG. 3 is an exemplary sectional view illustrating the flash driveaccording to the embodiment;

FIG. 4 is an exemplary sectional view illustrating the flash driveaccording to the embodiment along a line F4-F4 in FIG. 3;

FIG. 5 is an exemplary perspective view illustrating the flash driveincluding a connector different from a connector in FIG. 1;

FIG. 6 is an exemplary sectional view illustrating the flash driveaccording to the embodiment along a line F6-F6 in FIG. 4; and

FIG. 7 is a block diagram illustrating an example of a configuration ofthe flash drive according to the embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, a semiconductor memory deviceincludes a casing, a substrate, a first electronic component, a secondelectronic component, a second connector, and an interposition member.The casing includes a first edge that forms the first opening that opensto outside. A first connector conforming to USB Type-A standard can passthrough the first opening and be held by the first edge. The substrateis housed in the casing. The first electronic component is mounted onthe substrate and stores therein information. The second electroniccomponent is mounted on the substrate and controls the first electroniccomponent. The second connector is mounted on the substrate and passesthrough the first opening away from at least a part of the first edge.The interposition member is interposed between an inner surface of thecasing and the second connector, is held by the inner surface, and holdsthe second connector.

One embodiment is described below with reference to FIG. 1 to FIG. 7.The present embodiment may include a plurality of expressions for aconstituent element according to the embodiment and the description ofthe element. The constituent element and description written with theplurality of expressions may be expressed in other non-describedmanners. Furthermore, the constituent element and description notdescribed with a plurality of expressions may also be expressed in othernon-described manners.

FIG. 1 is an exemplary perspective view illustrating a flash drive 10according to one embodiment. FIG. 2 is an exemplary exploded perspectiveview illustrating the flash drive 10 according to the embodiment. Theflash drive 10 is an example of a semiconductor memory device, and canbe also referred to as, for example, USB flash drive (UFD), USB memory,electronic device, semiconductor device, USB device, storage, auxiliarystorage, removable medium, or device. The semiconductor memory devicecan be another device.

As illustrated in FIG. 1, the flash drive 10 according to the presentembodiment has, for example, a plate shape having a substantially ovalcross-section. The flash drive 10 can have other shapes.

As illustrated in the respective drawings, in the present specification,an X axis, a Y axis, and a Z axis are defined. The X axis, the Y axis,and the Z axis are orthogonal to each other. The X axis lies along thewidth of the flash drive 10. The Y axis lies along the length of theflash drive 10. The Z axis lies along the thickness of the flash drive10.

As illustrated in FIG. 2, the flash drive 10 includes a case 11 and amodule 12. The module 12 includes a substrate 13, two flash memories 14,a controller 15, and a connector 16A. The flash drive 10 according tothe present embodiment also includes a spacer 17.

The case 11 is an example of the casing. The flash memories 14 are anexample of a first electronic component, and can be also referred to as,for example, nonvolatile memories, memories, or storage. The controller15 is an example of a second electronic component, and can be alsoreferred to as, for example, control unit. The connector 16A is anexample of a second connector, and can be also referred to as, forexample, plug, connection terminal, insertion, or connection. The spacer17 is an example of an interposition member.

The substrate 13, the flash memories 14, the controller 15, a part ofthe connector 16A, and the spacer 17 are housed in an inner space 19 ofthe case 11. The inner space 19 is a space inside the case 11 and anexample of an inside of the casing.

The connector 16A projects from the case 11 and can be covered with, forexample, a lid (a cap) attachable to the case 11. The case 11 is, forexample, made of metal. The case 11 can be made of other materials suchas synthetic resin.

The substrate 13 is, for example, a printed circuit board (PCB). Thesubstrate 13 can be another substrate such as a flexible printed circuitboard (FPC). The substrate 13 has a substantially quadrangular(rectangular) plate shape extending in an X-Y plane. The substrate 13can have another shape.

FIG. 3 is an exemplary sectional view illustrating the flash drive 10according to the embodiment. As illustrated in FIG. 3, the substrate 13includes a first surface 21 and a second surface 22 which aresubstantially flat. The first surface 21 faces in a positive Z-axisdirection (as indicated by the Z-axis arrow). The second surface 22 isopposite the first surface 21 and faces in a negative Z-axis direction(an opposite direction to the direction indicated by the Z-axis arrow).

FIG. 4 is an exemplary sectional view illustrating the flash drive 10according to the embodiment along a line F4-F4 in FIG. 3. As illustratedin FIG. 4, the substrate 13 includes a first end edge 25, a second endedge 26, two first side edges 27, and two second side edges 28. Thefirst end edge 25 is an example of an end of the substrate in a firstdirection. Each of the first end edge 25, the second end edge 26, thefirst side edges 27, and the second side edges 28 is connected to anedge of the first surface 21 and an edge of the second surface 22.

The first end edge 25 is the end of the substrate 13 in a positive Yaxis direction (as indicated by the Y-axis arrow). The positive Y axisdirection is an example of the first direction. The second end edge 26is the end of the substrate 13 in a negative Y axis direction (anopposite direction to the direction indicated by the Y-axis arrow). Thenegative Y axis direction is an opposite direction to the positive Yaxis direction and is an example of a second direction. The first endedge 25 and the second end edge 26 extend in the X-axis direction. TheX-axis direction includes a positive X-axis direction (as indicated bythe X-axis arrow) and a negative X-axis direction (an opposite directionto the direction indicated by the X-axis arrow).

The two first side edges 27 are opposite ends of the substrate 13 in theX-axis direction. The first side edges 27 extend in the Y-axis directionand are connected to opposite ends of the second end edges 26 in theX-axis direction. The Y-axis direction includes the positive andnegative Y-axis directions.

The two second side edges 28 are near the first end edge 25 and theopposite ends of the substrate 13 in the X-axis direction. The secondside edges 28 extend in the Y-axis direction and are respectivelyconnected to the opposite ends of the first end edges 25 in the X-axisdirection. In the X-axis direction, a distance between the two secondside edges 28 is shorter than a distance between the two first sideedges 27.

The substrate 13 has a substantially oblong shape extending in theY-axis direction in a planar view facing in the Z-axis direction as inFIG. 4. The Z-axis direction includes the positive and negative Z-axisdirections. A distance between the first end edge 25 and the second endedge 26 in the Y-axis direction is longer than a distance between thetwo first side edges 27 in the X-axis direction.

The first end edge 25 and the second end edge 26 form the short sides ofthe substrate 13. The first side edges 27 and the second side edges 28form the long sides of the substrate 13. The Y-axis direction can bereferred to as “long-side direction of the substrate 13”. The X-axisdirection can be referred to as “short-side direction of the substrate13”.

As illustrated in FIG. 3, the two flash memories 14 are separatelymounted on the first surface 21 and the second surface 22 of thesubstrate 13. For example, a plurality of terminals is arranged in theflash memories 14 and electrically connected to a plurality ofelectrodes provided on the first surface 21 and the second surface 22with solder. The flash memories 14 can be mounted on either of the firstsurface 21 and the second surface 22.

The flash memory 14 is an electronic component that can store thereininformation, and is, for example, a NAND flash memory. The flash drive10 can also include other nonvolatile memories such as a NOR flashmemory, a magnetoresistive random access memory (MRAM), a phase changerandom access memory (PRAM), a resistive random access memory (ReRAM),or a ferroelectric random access memory (FeRAM).

The controller 15 is mounted on the first surface 21 of the substrate13. For example, a plurality of terminals is disposed on the controller15 and electrically connected to electrodes provided on the firstsurface 21 with solder. The controller 15 can be mounted on the secondsurface 22. For example, the controller 15 controls the flash memories14 and controls communication between the flash drive 10 and a hostdevice. The controller 15 is located between the flash memory 14 and thefirst end edge 25 of the substrate 13 in the Y-axis direction.

The connector 16A is, for example, a male connector (a plug) conformingto USB Type-C standard. The USB Type-C standard includes, for example,USB 2.0 Type-C, USB 3.1 Gen1 Type-C, and USB 3.1 Gen2 Type-C. Theconnector 16A includes a shell 31 made of metal. The shell 31 includesan insertion 32 and a mount 33.

The insertion 32 has a substantially oval cross-section and extends inthe Y-axis direction. The insertion 32 includes a front end 32 a and abase end 32 b. In the present specification, nominal designation such as“front”, “rear”, “top”, and “bottom” is intended only for the sake ofconvenience and not intended to limit positions and directions.

The front end 32 a is the end of the insertion 32 in the positive Y-axisdirection. The base end 32 b is the end of the insertion 32 in thenegative Y-axis direction and is opposite the front end 32 a. The baseend 32 b and the first end edge 25 of the substrate 13 face each other.

The front end 32 a is provided with an opening. A plurality ofelectrodes is arranged in the opening. The number of electrodes is, forexample, twenty four and can be less or more than twenty four. Theinsertion 32 is inserted into a USB connector (a female connector, asocket), for example, of the host device. An electrode in the socket isinserted into the opening of the front end 32 a and electricallyconnected to the electrode of the connector 16A. Thereby, the flashdrive 10 and the host device are electrically connected.

The mount 33 extends from the base end 32 b of the insertion 32 alongthe second surface 22 of the substrate 13 in the negative Y-axisdirection. The mount 33 includes a rear end 33 a. The rear end 33 a isan example of an end of the second connector in the second direction.

In the present embodiment, the rear end 33 a is the end of the mount 33and the end of the connector 16A in the negative Y-axis direction. Thefront end 32 a of the insertion 32 is the end of the connector 16A inthe positive Y-axis direction.

The mount 33 is provided with a plurality of pins. The pins areconnected to the electrodes in the opening of the front end 32 a, andare electrically connected to the electrodes on the second surface 22with solder. That is, the connector 16A is mounted on the second surface22 of the substrate 13. The connector 16A can be mounted on the firstsurface 21 or can be electrically connected to the electrodes on both ofthe first surface 21 and the second surface 22.

As illustrated in FIG. 2, the case 11 includes a first cover 41 and asecond cover 42. The first cover 41 covers the first surface 21 of thesubstrate 13. The second cover 42 covers the second surface 22 of thesubstrate 13.

The first cover 41 and the second cover 42 are fixed to each other,forming the case 11, for example, by a snap-fit connection or withscrews. Alternatively, the first cover 41 and the second cover 42 can beintegrally formed, for example.

As illustrated in FIG. 3, the inner space 19 of the case 11 includes achamber 51 and a first opening 52. A part of the substrate 13, the flashmemories 14, the controller 15, a part of the connector 16A, and a partof the spacer 17 are housed in the chamber 51. The chamber 51 iscommunicated with outside of the case 11 through the first opening 52. Apart of the substrate 13, a part of the connector 16A, and a part of thespacer 17 are housed in the first opening 52.

The case 11 includes an end face 55 and an inner surface 56. The endface 55 is the end of the case 11 in the positive Y-axis direction. Theend face 55 is substantially flat and faces in the positive Y-axisdirection. The first opening 52 opens to the end face 55. Thus, thefirst opening 52 opens to the outside of the case 11. The inner surface56 faces the inside of the case 11 and forms (defines) the inner space19. The inner surface 56 includes a first edge 57 that forms (defines)the first opening 52.

The first opening 52 is a hole having a substantially quadrangular(rectangular) cross-section and extending in the Y-axis direction. Thatis, the first edge 57 is also a substantially quadrangular (rectangular)tubular face. As illustrated in FIG. 1, the first edge 57 includes fourfirst flat faces 57 a, 57 b, 57 c, and 57 d.

The first flat face 57 a faces in the positive Z-axis direction. Thefirst flat face 57 b faces in the negative Z-axis direction. The firstflat faces 56 a and 56 b face each other. The first flat face 57 c facesin the positive X-axis direction. The first flat face 57 d faces in thenegative X-axis direction. The first flat faces 57 c and 57 d face eachother. The lengths of the first flat faces 57 a and 57 b in the X-axisdirection are longer than the lengths of the first flat faces 57 c and57 d in the Z-axis direction.

FIG. 5 is an exemplary perspective view illustrating the flash drive 10including a connector 16B instead of the connector 16A according to theembodiment. The connector 16B is an example of the first connector andis a male connector conforming to USB Type-A standard. The USB Type-Astandard is also referred to as “USB Standard-A” and includes, forexample, USB 2.0 Type-A, USB 3.1 Gen1 Type-A, and USB 3.1 Gen2 Type-A.The USB Type-A male connector can be also referred to as, for example,“USB-A connector” or “USB-A plug”.

As illustrated in FIG. 5, the first opening 52 has substantially thesame cross-section as that of the USB Type-A connector 16B, and has asize and a shape sufficient to allow the connector 16B to passtherethrough. Specifically, the first opening 52 has a substantiallyquadrangular cross-section of about 12 millimeters×4.5 millimeters.

The connector 16B, while passing through the first opening 52 in theY-axis direction, is held by the first edge 57. In other words, theconnector 16B is fitted into the first edge 57 and the first edge 57surrounds the connector 16B so as to restrict the movement of theconnector 16B with respect to the case 11 in a direction intersectingwith the Y-axis direction.

The first flat faces 57 a, 57 b, 57 c, and 57 d contact the connector16B or face the connector 16B with a small gap. The first flat face 57 arestricts the movement of the connector 16B with respect to the case 11in the negative Z-axis direction. The first flat face 57 b restricts themovement of the connector 16B with respect to the case 11 in thepositive Z-axis direction. The first flat face 57 c restricts themovement of the connector 16B with respect to the case 11 in thenegative X-axis direction. The first flat face 57 d restricts themovement of the connector 16B with respect to the case 11 in thepositive X-axis direction.

The first opening 52 and the first edge 57 can be used for otherpurposes, so long as the USB Type-A connector 16B can pass through thefirst opening 52 and be held by the first edge 57. For example, thefirst opening 52 and the first edge 57 can be formed such that aconnector conforming to another standard can pass through the firstopening 52 and be held by the first edge 57.

As described above, the USB Type-A connector 16B can be fitted in thefirst opening 52. However, in the present embodiment, the USB Type-Cconnector 16A and the spacer 17 are fitted in the first opening 52.

As is obvious from FIG. 1 and FIG. 5, the connector 16A is smaller thanthe connector 16B. As illustrated in FIG. 2, the connector 16A ismounted on the substrate 13 and extends from the substrate 13 in thepositive Y-axis direction. The connector 16A then projects to outside ofthe case 11 through the first opening 52.

In an X-Z plane orthogonal to the Y axis, the cross-section of theconnector 16A is smaller than the cross-section of the first opening 52.Inside the first opening 52, the connector 16A is located apart from thefirst edge 57. The connector 16A can be separated from a part of thefirst edge 57 and contact with another part of the first edge 57.

The spacer 17 is made of metal and has a substantially quadrangular(rectangular) tubular shape, for example. The spacer 17 can be made ofother materials such as synthetic resin or can have other shapes.

The spacer 17 is housed in the first opening 52 and surrounds theconnector 16A. Thus, the spacer 17 is interposed between the first edge57 of the case 11 and the shell 31 of the connector 16A, closing the gapbetween the first edge 57 and the shell 31. The spacer 17 includes anend wall 61, a bottom wall 62, a top wall 63, and two side walls 64.

The end wall 61 is a substantially quadrangular wall of about 12millimeters×4.5 millimeters extending in the X-Z plane. As illustratedin FIG. 3, the end wall 61 includes an outer surface 61 a and an innersurface 61 b that are substantially flat. The outer surface 61 a facesin the positive Y-axis direction. The inner surface 61 b is opposite theouter surface 61 a and faces in the negative Y-axis direction.

With the spacer 17 housed in the first opening 52, the outer surface 61a and the end face 55 of the case 11 are aligned with each other onsubstantially the same plane. The outer surface 61 a can be separatedfrom the end face 55 in the positive or negative Y-axis direction.

The end wall 61 is provided with a second opening 67. The second opening67 extends through the end wall 61 in the Y-axis direction and opens tothe outer surface 61 a and the inner surface 61 b. The end wall 61further includes a second edge 68 forming (defining) the second opening67.

As illustrated in FIG. 2, the second opening 67 is a hole having asubstantially oval cross-section. Thus, the second edge 68 is also asubstantially oval tubular face. The second edge 68 includes two secondflat faces 68 a and 68 b and two curved faces 68 c and 68 d.

The second flat face 68 a faces in the positive Z-axis direction. Thesecond flat face 68 b faces in the negative Z-axis direction. The secondflat faces 68 a and 68 b face each other. The curved face 68 c isarc-like recessed in the negative X-axis direction. The curved face 68 dis arc-like recessed in the positive X-axis direction. The curved faces68 c and 68 d face each other.

The second opening 67 has substantially the same size and shape as theend face of the USB Type-C connector 16A, and allows the insertion 32 ofthe connector 16A to be inserted therethrough. Specifically, the secondopening 67 has a substantially oval cross-section of about 8.34millimeters×2.56 millimeters. The insertion 32 of the connector 16Aprojects to outside of the case 11 through the second opening 67 in theY-axis direction.

By inserting the insertion 32 of the connector 16A through the secondopening 67, the connector 16A is held by the second edge 68. In otherwords, the insertion 32 of the connector 16A is fitted into the secondedge 68, and the second edge 68 surrounds the insertion 32 of theconnector 16A so as to restrict the movement of the connector 16A withrespect to the spacer 17 in a direction intersecting with the Y-axisdirection.

The second flat faces 68 a and 68 b and the curved faces 68 c and 68 dall contact with the insertion 32 of the connector 16A or face theinsertion 32 with a small gap. The second flat face 68 a restricts themovement of the connector 16A with respect to the spacer 17 in thenegative Z-axis direction. The second flat face 68 b restricts themovement of the connector 16A with respect to the spacer 17 in thepositive Z-axis direction. The curved face 68 c restricts the movementof the connector 16A with respect to the spacer 17 in the negativeX-axis direction. The curved face 68 d restricts the movement of theconnector 16A with respect to the spacer 17 in the positive X-axisdirection.

As illustrated in FIG. 3, the bottom wall 62 extends in the negativeY-axis direction from the end of the end wall 61 in the negative Z-axisdirection. The bottom wall 62 and the second flat face 68 a of thesecond edge 68 contact the connector 16A or faces the connector 16A witha small gap. The bottom wall 62 restricts the movement of the connector16A with respect to the spacer 17 in the negative Z-axis direction.

The top wall 63 extends in the negative Y-axis direction from the end ofthe end wall 61 in the positive Z-axis direction. The top wall 63 isseparated from the connector 16A. The top wall 63 and the second flatface 68 b of the second edge 68 can face the connector 16A.

As illustrated in FIG. 2, the top wall 63 is provided with a cutout 63a. The cutout 63 a is recessed in the positive Y-axis direction from anend 63 b of the top wall 63 in the negative Y-axis direction. By thecutout 63 a, the top wall 63 is spaced apart from the controller 15.

As illustrated in FIG. 4, the two side walls 64 extend in the negativeY-axis direction from the X-axial opposite ends of the end wall 61. TheZ-axial opposite ends of the side walls 64 are connected to the bottomwall 62 and the top wall 63. The two side walls 64 contact with thesecond side edges 28 of the substrate 13 or face the second side edges28 with a small gap. The two side walls 64 restrict the movement of thesubstrate 13 with respect to the spacer 17 in the X-axis direction.

As illustrated in FIG. 1, the spacer 17 is interposed between theconnector 16A and the first edge 57 and is held by the first edge 57. Inother words, the spacer 17 is fitted into the first edge 57, and thefirst edge 57 surrounds the spacer 17 so as to restrict the movement ofthe spacer 17 with respect to the case 11. The first flat faces 57 a, 57b, 57 c, and 57 d of the first edge 57 contact with the spacer 17 orface the spacer 17 with a small gap.

The first flat face 57 a faces the bottom wall 62 and restricts themovement of the spacer 17 with respect to the case 11 in the negativeZ-axis direction. The first flat face 57 b faces the top wall 63 andrestricts the movement of the spacer 17 with respect to the case 11 inthe positive Z-axis direction. The first flat face 57 c faces one of theside walls 64 and restricts the movement of the spacer 17 with respectto the case 11 in the negative X-axis direction. The first flat face 57d faces the other of the side walls 64 and restricts the movement of thespacer 17 with respect to the case 11 in the positive X-axis direction.The spacer 17 can be held by the inner surface 56 away from the firstedge 57 in the negative Y-axis direction.

The shell 31 of the connector 16A comes into contact with the secondedge 68 of the metal spacer 17. The spacer 17 also comes into contactwith the first edge 57 of the metal case 11. Thus, the shell 31 iselectrically connected to the case 11 via the spacer 17. The shell 31 isconnected, for example, to the ground of a circuit of the module 12.

The spacer 17 is not directly fixed to the case 11 but fixed to themodule 12 including the substrate 13 and the connector 16A. Because ofthis, along with Y-axial movement of the module 12 with respect to thecase 11, the spacer 17 can move in the Y-axis direction with respect tothe case 11. The spacer 17 can be directly fixed to the case 11.

FIG. 6 is an exemplary sectional view illustrating the flash drive 10according to the embodiment along a line F6-F6 in FIG. 4. The spacer 17further includes a first restrictor 71 illustrated in FIG. 3, two secondrestrictors 72 illustrated in FIG. 4, and two third restrictors 73 andtwo fourth restrictors 74 illustrated in FIG. 6. The spacer 17 is fixedto the module 12 including the substrate 13 and the connector 16Athrough the bottom wall 62, the side walls 64, the second edge 68, thefirst restrictor 71, the second restrictors 72, the third restrictors73, and the fourth restrictors 74.

As illustrated in FIG. 3, the first restrictor 71 is located on thebottom wall 62 and includes an elastic portion 71 a and a stop 71 b. Theelastic portion 71 a is a part of the bottom wall 62 extending in thenegative Y-axis direction from the vicinity of the end wall 61. Theelastic portion 71 a can be elastically bent away from the connector 16Aabout the fulcrum in the vicinity of the end wall 61. The stop 71 bprojects in the positive Z-axis direction from the end of the elasticportion 71 a in the negative Y-axis direction.

The stop 71 b contacts the rear end 33 a of the mount 33 of theconnector 16A or faces the rear end 33 a with a small gap. The stop 71 brestricts the movement of the connector 16A with respect to the spacer17 in the negative Y-axis direction.

By the elastic deformation of the elastic portion 71 a away from theconnector 16A, the stop 71 b is moved away from the rear end 33 a of theconnector 16A in the negative Z-axis direction. Thereby, the stop 71 ballows the movement of the connector 16A with respect to the spacer 17in the negative Y-axis direction.

The elastic portion 71 a is located between the connector 16A and thefirst flat face 57 a of the first edge 57. The first flat face 57 afaces the elastic portion 71 a and restricts the elastic portion 71 afrom elastically deforming away from the connector 16A. In this manner,with the spacer 17 interposed between the connector 16A and the firstedge 57, the stop 71 b is prevented from moving apart from the rear end33 a of the connector 16A in the negative Z-axis direction.

As illustrated in FIG. 4, the second restrictors 72 project from theinner surface 61 b of the end wall 61 in the negative Y-axis direction.The second restrictors 72 contact the first end edge 25 of the substrate13 or face the first end edge 25 with a small gap. The secondrestrictors 72 restrict the movement of the substrate 13 with respect tothe spacer 17 in the positive Y-axis direction.

In the Y-axis direction, a distance between the stop 71 b of the firstrestrictor 71 and the second restrictors 72 is substantially equal to adistance between the first end edge 25 of the substrate 13 and the rearend 33 a of the connector 16A. Thus, the first restrictor 71 and thesecond restrictors 72 restrict the movement of the module 12 includingthe substrate 13 and the connector 16A with respect to the spacer 17 inthe Y-axis direction.

As described in FIG. 6, the two third restrictors 73 project from thetwo side walls 64. The third restrictors 73 contact the first surface 21of the substrate 13 or face the first surface 21 with a small gap. Thethird restrictors 73 restrict the movement of the substrate 13 withrespect to the spacer 17 in the positive Z-axis direction.

The two fourth restrictors 74 project from the two side walls 64. Thefourth restrictors 74 contact the second surface 22 of the substrate 13or face the second surface 22 with a small gap. The fourth restrictors74 restrict the movement of the substrate 13 with respect to the spacer17 in the negative Z-axis direction.

Grooves 76 are provided between the third restrictors 73 and the fourthrestrictors 74. The grooves 76 extend in the Y-axis direction and areopen in the negative Y-axis direction. The second side edges 28 of thesubstrate 13 are housed in the grooves 76.

As described above, the connector 16A is mounted on the substrate 13.The bottom wall 62, the side walls 64, the second edge 68, the firstrestrictor 71, the second restrictors 72, the third restrictors 73, andthe fourth restrictors 74 restrict the movement of the connector 16A andthe substrate 13 with respect to the spacer 17 in the X-axis direction,the Y-axis direction, and the Z-axis direction. This fixes the spacer 17to the module 12 including the connector 16A and the substrate 13.

As illustrated in FIG. 2, for example, the connector 16A, while mountedon the substrate 13, is inserted through the second opening 67. In themanufacturing process of the flash drive 10, the flash memories 14, thecontroller 14, and the connector 16A are first mounted on the substrate13. That is, the connector 16A is inserted through the second opening 67in the positive Y-axis direction in the assembled module 12.

As illustrated in FIG. 6, while the connector 16A is inserted throughthe second opening 67, the second side edges 28 of the substrate 13 arefitted into the grooves 76. Thus, the third restrictors 73 and thefourth restrictors 74 forming the grooves 76 guide the substrate 13.

Further, while the connector 16A is inserted through the second opening67, the stop 71 b of the first restrictor 71 is pressed by the connector16A to bend the elastic portion 71 a elastically. When the first endedge 25 of the substrate 13 abuts on the second restrictors 72, theelastic portion 71 a is restored so that the stop 71 b faces the rearend 33 a of the mount 33. In this manner, the spacer 17 is fixed to theconnector 16A and the substrate 13.

The connector 16A mounted on the substrate 13 is detachable from thesecond opening 67. For example, by elastically bending the elasticportion 71 a of the first restrictor 71, the stop 71 b is displaced fromthe connector 16A. Thereby, the connector 16A can be pulled out from thesecond opening 67 in the negative Y-axis direction, to detach theconnector 16A and the substrate 13 from the spacer 17.

As illustrated in FIG. 4, the case 11 includes a plurality of first ribs81, a plurality of second ribs 82, and a third rib 83. The first ribs 81are an example of a fifth restrictor. The first ribs 81, the second ribs82, and the third rib 83 project from the inner surface 56 of the case11.

The two first side edges 27 of the substrate 13 are each provided with acutout 85. A part of each first rib 81 is housed in the cutout 85. Thefirst ribs 81 face the edges of the cutouts 85. Another part of eachfirst rib 81 faces the first surface 21 and the second surface 22 of thesubstrate 13. Thereby, the first ribs 81 restrict the movement of thesubstrate 13 with respect to the case 11 in the Y-axis direction and theZ-axis direction.

A part of each second rib 82 faces the first side edge 27. Another partof the second rib 82 faces the first surface 21 and the second surface22 of the substrate 13. Thus, the second ribs 82 restrict the movementof the substrate 13 with respect to the case 11 in the X-axis directionand the Z-axis direction.

The third rib 83 faces the second end edge 26. Thus, the third rib 83restricts the movement of the substrate 13 with respect to the case 11in the negative Y-axis direction. As described above, the first ribs 81,the second ribs 82, and the third rib 83 fix the substrate 13 to thecase 11. The spacer 17 is fixed to the case 11 indirectly via thesubstrate 13.

FIG. 7 is a block diagram illustrating an example of a configuration ofthe flash drive 10 according to the embodiment. As illustrated in FIG.7, the controller 15 controls data transmission between the connector16A and the flash memories 14.

The controller 15 includes a USB interface (I/F) 15 a, an MPU 15 b, aROM 15 c, a RAM 15 d, a memory interface (I/F) 15 e, and an internal bus15 f. The USB I/F 15 a, the MPU 15 b, the ROM 15 c, the RAM 15 d, thememory I/F 15 e, and the internal bus 15 f are formed, for example, onone semiconductor substrate.

The USB I/F 15 a receives data and commands from a host device via theconnector 16A. The data and the commands are written in standard formatof, for example, a small computer system interface (SCSI). The USB I/F15 a reads data from the flash memory 14 and outputs the data to thehost device via the connector 16A according to the SCSI standard format.

The MPU 15 b processes a command received from the host device and datareceived from the flash memories 14 using, for example, the ROM 15 c andthe RAM 15 d. When the flash drive 10 is connected to the host device,the MPU 15 b performs authentication between the host device and theflash drive 10.

The ROM 15 c holds data and programs required for the processing by theMPU 15 b. The RAM 15 d functions as a work area for the processing bythe MPU 15 b. The RAM 15 d is, for example, a volatile semiconductormemory such as a DRAM.

The memory I/F 15 e is connected to the flash memories 14, for example,through wiring. The memory I/F 15 e transfers a command and datareceived by the USB I/F 15 a to the flash memories 14 and transfers dataread from the flash memories 14 to the USB I/F 15 a in response to acommand from the MPU 15 b.

The flash memory 14 reads and outputs data in response to a read commandfrom the controller 15. The flash memory 14 records data in response toa write command from the controller 15.

In the flash drive 10 according to the embodiment described above, theconnector 16A passes through the first opening 52 with spacing from atleast a part of the first edge 57 in which the USB Type-A connector 16Bcan be held. The spacer 17 is interposed between the inner surface 56 ofthe case 11 including the first edge 57 and the connector 16A, is heldby the inner surface 56, and holds the connector 16A. Thereby, theconnector 16A is stably held, while passing through the first opening 52through which the connector 16B is passable, for example. Thus, theconnector 16A can be inserted through the first opening 52 instead ofthe connector 16B, enabling shared use of the case 11 by different typesof flash drives, i.e., the flash drive 10 illustrated in FIG. 5including the connector 16B and the flash drive 10 illustrated in FIG. 1including the connector 16A. The shared use of the case 11 leads toreducing mold manufacturing cost, a design and evaluation period of thecase 11, and a setup period of manufacturing facilities, for example,thereby reduce the manufacturing cost of the flash drive 10.

The spacer 17 is interposed between the first edge 57 and the connector16A and is held by the first edge 57. Thereby, the spacer 17 fills thegap between the first edge 57 and the connector 16A, which can avoiddeterioration in the design quality of the flash drive 10 including theconnector 16A.

The spacer 17 includes the second edge 68 forming the second opening 67.The connector 16A passes through the second opening 67 and is held bythe second edge 68. Thus, the spacer 17 and the connector 16A can beeasily attached to each other, thereby facilitating the assembly of theflash drive 10.

The connector 16A, while mounted on the substrate 13, can be insertedthrough the second opening 67 detachably. Thereby, the spacer 17 can beattached to the connector 16A mounted on the substrate 13. That is, thespacer 17 and the connector 16A can be easily attached to each other,thereby facilitating the assembly of the flash drive 10.

The spacer 17 includes the first restrictor 71, which faces the rear end33 a of the connector 16A to restrict the movement of the connector 16Awith respect to the spacer 17 in the negative Y-axis direction, and thesecond restrictors 72, which face the first end edge 25 of the substrate13 to restrict the movement of the substrate 13 with respect to thespacer 17 in the positive Y-axis direction. The first restrictor 71elastically deforms and moves away from the rear end 33 a of theconnector 16A to allow the movement of the connector 16A with respect tothe spacer 17 in the negative Y-axis direction. Thereby, the spacer 17is unlikely to be displaced from the connector 16A. Further, the elasticdeformation of the first restrictor 71 facilitates the attachment of thespacer 17 and the connector 16A, thereby facilitating the assembly ofthe flash drive 10.

The spacer 17 includes the third restrictors 73, which face the firstsurface 21 of the substrate 13 to restrict the movement of the substrate13 with respect to the spacer 17 in the positive Y-axis direction, andthe fourth restrictors 74, which face the second surface 22 of thesubstrate 13 to restrict the movement of the substrate 13 with respectto the spacer 17 in the negative Y-axis direction. Thus, both theconnector 16A and the substrate 13 are held by the first edge 57, thethird restrictors 73, and the fourth restrictors 74. That is, thesubstrate 13 and the connector 16A mounted on the substrate 13 arestably held.

The connector 16A includes the shell 31 electrically connected to thecase 11 via the spacer 17. This enables the ground of the connector 16Ato connect to the metal case 11, for example.

The spacer 17 is indirectly fixed to the case 11 through the connector16A and the substrate 13. This eliminates the necessity for the case 11to additionally include a part for fixing the spacer 17, which furtherfacilitates the shared use of the case 11 by the flash drive 10including the connector 16B and the flash drive 10 including theconnector 16A.

The connector 16A conforms to the USB Type-C standard. That is, the USBType-C connector 16A can be inserted through the first opening 52instead of the USB Type-A connector 16B, for example. Thus, the flashdrive 10 including the connector 16B and the flash drive 10 includingthe connector 16A can share the case 11, the flash memories 14, and thecontroller 15, thereby reducing the manufacturing cost of the flashdrives 10.

In the embodiment described above, the connector 16A conforms to the USBType-C standard. Alternatively, the connector 16A can also conform toother standards such as USB Mini-A, USB Mini-B, USB Micro-A, USBMicro-B, USB Type-C, and Lightning®. The connector 16A conforming toanother standard is also smaller than the USB Type-A connector 16B.

According to at least the embodiment described above, a second connectorpasses through a first opening with spacing from at least a part of afirst edge by which a first connector conforming to USB Type-A standardcan be held. An interposition member is interposed between an innersurface of a casing and the second connector, is held by the innersurface, and holds the second connector. Thus, the second connector isstably held, while passing through the first opening through which thefirst connector is to pass. That is, the second connector can beinserted through the first opening instead of the first connector,enabling shared use of the casing by a semiconductor memory deviceincluding the first connector and another semiconductor memory deviceincluding the second connector. By the shared use of the casing, forexample, it is made possible to reduce mold manufacturing costs, thedesigning and evaluation period of the casing, and the setup period ofthe manufacturing facilities, thereby enabling cost reduction of thesemiconductor memory device.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A semiconductor memory device comprising: acasing including a first edge that forms a first opening that opens tooutside and allows a first connector to pass through and be held by thefirst edge, the first connector conforming to USB Type-A standard; asubstrate housed in the casing; a first electronic component mounted onthe substrate, the first electronic component that stores thereininformation; a second electronic component mounted on the substrate, thesecond electronic component that controls the first electroniccomponent; a second connector mounted on the substrate, the secondconnector that passes through the first opening away from at least apart of the first edge; and an interposition member that is interposedbetween an inner surface of the casing and the second connector, is heldby the inner surface, and holds the second connector.
 2. Thesemiconductor memory device according to claim 1, wherein the casing ismade of metal, the interposition member is made of metal, and the secondconnector includes a shell electrically connected to the casing via theinterposition member.
 3. The semiconductor memory device according toclaim 1, wherein the interposition member includes a second edge thatforms a second opening, and the second connector passes through thesecond opening so as to be held by the second edge.
 4. The semiconductormemory device according to claim 3, wherein the second connector, whilemounted on the substrate, can be inserted through the second openingdetachably.
 5. The semiconductor memory device according to claim 4,wherein the second connector extends from the substrate in a firstdirection, the interposition member includes a first restrictor and asecond restrictor, the first restrictor that faces an end of the secondconnector in a second direction opposite to the first direction torestrict movement of the second connector with respect to theinterposition member in the second direction, the second restrictor thatfaces an end of the substrate in the first direction to restrictmovement of the substrate with respect to the interposition member inthe first direction, and the first restrictor elastically deforms tomove away from an end of the second connector, and allows movement ofthe second connector with respect to the interposition member in thesecond direction.
 6. The semiconductor memory device according to claim5, wherein the substrate includes a first surface on which the firstelectronic component is mounted, and a second surface opposite the firstsurface, and the interposition member includes a third restrictor and afourth restrictor, the third restrictor that faces the first surface torestrict movement of the substrate with respect to the interpositionmember in a direction in which the first surface faces, the fourthrestrictor that faces the second surface to restrict movement of thesubstrate with respect to the interposition member in a direction inwhich the second surface faces.
 7. The semiconductor memory deviceaccording to claim 6, wherein the substrate is provided with a cutout,and the casing includes a fifth restrictor which is at least partiallyhoused in the cutout, and faces an edge of the cutout to restrictmovement of the substrate in the first direction and the seconddirection.
 8. The semiconductor memory device according to claim 3,wherein the casing includes an end face to which the first opening isopen, the interposition member includes an outer surface to which thesecond opening is open, and the outer surface and the end face arelocated on the same plane.
 9. The semiconductor memory device accordingto claim 1, wherein the inner surface includes the first edge, and theinterposition member is interposed between the first edge and the secondconnector and is held by the first edge.
 10. The semiconductor memorydevice according to claim 1, wherein the second connector conforms toUSB Type-C standard.
 11. The semiconductor memory device according toclaim 10, wherein the inner surface includes the first edge, and theinterposition member is interposed between the first edge and the secondconnector and is held by the first edge.
 12. The semiconductor memorydevice according to claim 10, wherein the interposition member includesa second edge that forms a second opening, and the second connectorpasses through the second opening so as to be held by the second edge.13. The semiconductor memory device according to claim 12, wherein thesecond connector, while mounted on the substrate, can be insertedthrough the second opening detachably.
 14. The semiconductor memorydevice according to claim 13, wherein the second connector extends fromthe substrate in a first direction, the interposition member includes afirst restrictor and a second restrictor, the first restrictor thatfaces an end of the second connector in a second direction opposite tothe first direction to restrict movement of the second connector withrespect to the interposition member in the second direction, the secondrestrictor that faces an end of the substrate in the first direction torestrict movement of the substrate with respect to the interpositionmember in the first direction, and the first restrictor elasticallydeforms to move away from an end of the second connector, and allowsmovement of the second connector with respect to the interpositionmember in the second direction.
 15. The semiconductor memory deviceaccording to claim 14, wherein the substrate includes a first surface onwhich the first electronic component is mounted, and a second surfaceopposite the first surface, and the interposition member includes athird restrictor and a fourth restrictor, the third restrictor thatfaces the first surface to restrict movement of the substrate withrespect to the interposition member in a direction in which the firstsurface faces, the fourth restrictor that faces the second surface torestrict movement of the substrate with respect to the interpositionmember in a direction in which the second surface faces.
 16. Thesemiconductor memory device according to claim 15, wherein the substrateis provided with a cutout, and the casing includes a fifth restrictorwhich is at least partially housed in the cutout, and faces an edge ofthe cutout to restrict movement of the substrate in the first directionand the second direction.
 17. The semiconductor memory device accordingto claim 12, wherein the casing includes an end face to which the firstopening is open, the interposition member includes an outer surface towhich the second opening is open, and the outer surface and the end faceare located on the same plane.
 18. The semiconductor memory deviceaccording to claim 10, wherein the casing is made of metal, theinterposition member is made of metal, and the second connector includesa shell electrically connected to the casing via the interpositionmember.